25 replies to this topic

[MaximumMax]

I am helping my wife with a honda build and have come into a few cooling system problems. I will give some info on what i have done so you can possible steer me in the right direction. I installed a 1.3lt in her civic hatchback 1986 which had a 1.5lt automatic trans. The 1.3 lt has the 5sd manual trans. I left the radiator in the car and capped the trans. cooling lines . We used the same cluster out the automatic . Now i am getting overheating not redlining but lines hair under the redline and then it drops to 3/4 on gauge. Now we have driven it short distances and it has not overheated but no real heat inside. I have replaced the thermostat twice in the last two weeks. The thermostat both times have been aftermarket stants 195 degree. The heat is getting to the heater core and the upper rad hose is hot. Both Heatercore hoses get hot and the heater core has been out and you can blow through it . I dont know the best way to burp the system because i thought there might be a airlock so i removed the hose after the heater valve on the heater hose inlet side to let any air escape and i was only getting a small stream of water there. I will go back and look again at the heater valve and make sure it didnt malfunction and i will try burping it on the other side of the heater core. In my mind the waterpump is not circulating enough but maybe you guys know of another check that would help me out.
I think that should come out of that heaterhose with close to the same pressure as the rad cap maybe you could help me here.
The bottom rad hose is hot and i have not heard the fan kick in yet either but it is -20 here and if you are driving it just the outside temp will keep it from overheating. I would appreciate any comments as I am stumped.

[4N2NR]

Sounds like the water pump is not pumping the volume it should. I would assume that very rarely will a cooling system air lock (I have never heard of one doing that). You should have a decent flow rate through your heater hose and the return hose. If they trickle, suspect your water pump.

[syko_tek1]

Sounds like the water pump. When I got my 3g it did the same thing. It had set for a while like about a year so i pulled the water pump and found the fins for the pump had rusted off.

[MaximumMax]

Sounds like the water pump. When I got my 3g it did the same thing. It had set for a while like about a year so i pulled the water pump and found the fins for the pump had rusted off.

Thankyou for your posts ..you confirmed what I didnt want to hear...lol
I know what i will be doing today and now i will know to change the waterpump on the one we will rebuild before installing down the road.
When doing the waterpump replace could you guys help me with the rotation of the crackshaft pulley bolt does it loosen clockwise or counterclock wise.
I am not sure but the crank rotation is counterclockwise so is the bolt the same or opposite. Again thankyou for the help.

Edited by MaximumMax, 19 January 2008 - 11:14 AM.

[JeepGirl]

When doing the waterpump replace could you guys help me with the rotation of the crackshaft pulley bolt does it loosen clockwise or counterclock wise.
I am not sure but the crank rotation is counterclockwise so is the bolt the same or opposite. Again thankyou for the help.

We are here at the shop right now, can anyone tell us whether or not the crankshaft pulley bolt comes off clockwise or counterclockwise? We don't want to hit it with the impact going the wrong way....


Thanks again everyone.

[Greg Gauper]

The crank pully bolt has normal threads i.e. "righty-tighty, lefty loosy".

[lil buddy]

Thankyou for your posts ..you confirmed what I didnt want to hear...lol
I know what i will be doing today and now i will know to change the waterpump on the one we will rebuild before installing down the road.
When doing the waterpump replace could you guys help me with the rotation of the crackshaft pulley bolt does it loosen clockwise or counterclock wise.
I am not sure but the crank rotation is counterclockwise so is the bolt the same or opposite. Again thankyou for the help.

all 84-87 civcs and crx rotate counterclockwise. the crank bolt will also loosen in the CC direction.

[JeepGirl]

Thanks guys.. we weren't sure, the manuals we have don't say.. some are opposite... we just wanted to be absolutely sure.

You guys rock! *Pats you on the back*

Edited by JeepGirl, 19 January 2008 - 01:30 PM.

[JeepGirl]

Ok.. we got the old water pump off... and there is NOTHING wrong with it... it looks just like the new one...


where should we look next? The rad? blockage in the block somewhere? Were really stumped now!

[tom91ita]

one other thing to consider is the radiator. i had one that the extended surface fins had corroded off the core but were still in place.

i tried to very gently wash some leaves and bugs off and with water pressure simulating pouring coffee into a mug, the fins fell out. i then pushed gently with my fingers and the things were crumbling off and just falling out.

[JeepGirl]

one other thing to consider is the radiator. i had one that the extended surface fins had corroded off the core but were still in place.

i tried to very gently wash some leaves and bugs off and with water pressure simulating pouring coffee into a mug, the fins fell out. i then pushed gently with my fingers and the things were crumbling off and just falling out.

Well we weren't much flow through the system with the car running... we had taken off the heatercore inlet hose to check for flow.. and it just dribbled out.. the car is overheating, weve tried 2 brand new stant 195deg t-stats to no avail... I'm ready to pull my hair out..

On the positive side.. it's getting a brand new waterpump and timing belt today... which will be useless untill we can figure out why the sucker won't flow..

I'll go see what he is up to and I'll report back..

This is starting to get rather frustrating..

[4N2NR]

Well, this is a bit of a puzzle...because the heater core shouldn't have any effect on cooling I would lean towards an obstructed radiator like tom91ita suggests if the water pump is good. The heater core is essentially a "Y" connection from the hot water side with a "Y" connection to the rad return side. A blocked heater core usually results in no heat and/or has a small leak that leaves an antifreeze residue on the windshield when on defrost. Unless it is a selaed system a small leak shouldn't cause overheating unless the coolant level drops too low. I had a Jeep Cherokee once with a sealed system and the plastic overflow resevoir had a crack in it that caused overheating. If you have the cooling system pressure tester you might try that and see if you have any leaks. Otherwise, I would check the rad for blockage. If you have a product like CLR (http://doitbest.com/...-sku-605900.dib) you could remove the rad and rubber band or tape plastic over the hose openings and put a gallon or two of CLR in, replace the cap, and rotate/agitate the rad for thirty minutes or so. Then flush the rad well. If a lot of debris comes out then you have to decide if it is clear enough now to use or if it needs to be recored or just replaced.

[JeepGirl]

Well what I just did was I connected a garden hose to the heatercore outlet>t-stat housing hose then I connected a drain hose onto the heatercore outlet then I cranked the water wide open.. and it was running through the system just fine.. So I think you might be right..

When we put the engine in the car last week, we filled the cooling system using a new fangled pressurized system that uses compressed air to push the coolant into the system.... What I think might have happened is that using that pressurizing gizmo forced all the crud in the rad down to the bottom where it only left a small passage for coolant to get through...

Sound about right?.....

[4N2NR]

Yes, that sounds plausible. The cooling system is relatively simple. The rad holds the liquid and transfers the heat. The hot liquid runs through veins and radiates the heat. The rad fan pulls cooler air around the veins and transfers the heat into the air cooling the liquid. The water pump moves the liquid through the engine where it heats up. The thermostat opens and closes at a set temperature so that the heater core which is a mini-radiator transfers heat into the passenger comparment. So...with a new stat and pump, the heat is not transfering from the rad to the air. Either there is insufficient air flow across the radiator or the radiator isn't allowing enough water into the water pump to go through the engine. Since you described the problem as a trikle of water that is hot I would next try to check the rad for obstructions. Unfortunately there is not an easy way to do that. You migh try removing the bottom rad hose and fill it with plain water from a hose and see if it drains quickly but that is not a real accurate test unless the water just dribbles out and the rad fills up and overflows out the top. Junked up veins can have narrow passages and retain more heat than a clear/clean system. The CLR trick may open them up enough to restore flow and heat transfer.

[JeepGirl]

Ok, that makes sense.

What we have done now is we flushed the rad as best we could while it was in the car... top to bottom and bottom to top and back again and it flowed clean and fast..

I took another look at the waterpump we took off and it looks like it has a bunch of rubber crap all over the one side.. so were almost thinking that the bearing might have been on it's way out... and with the belt tension on it I think it may not have been working like it should.

Were about to test the temp sending unit and the fan... as we haven't seen nor heard the fan fire up since we owned the car... once that's all done, were going to button everything back up and start it... if we still have issues I'm going to have to say it's the t-stat again.. but what are the odds of getting two bad t-stats in a row?


On the plus side our little 1.3 now has a new pump and timing belt

Edited by JeepGirl, 19 January 2008 - 04:17 PM.